1. Technical Field
The present invention relates in general to set-creating data processing operations, and in particular to searching operations which are performed in a data processing environment.
2. Description of the Related Art
Modern data processing systems allow operators to manipulate data at astounding rates; processing speeds of microprocessors in data processing systems have long ago ceased to be a major impediment to the speed and efficiency of most operator activities. Instead cumbersome user interfaces have developed into a potentially serious impediment to efficient operator interaction with the data processing system. The operations of opening, positioning, sizing and closing windows can place considerable strain on a user, particularly when complicated tasks are being performed or when the computer display screen is crowded with overlapping windows. This is especially true when an operator uses a data processing system to create and manipulate sets of data. One particularly useful set-creating activity is the use of set operations to search databases or software objects. Such operations are quite common, and include full-text key word searching, full-text character string searching, and descriptor field searching.
For example, key word or character string search operations may be used to search commercial databases containing and identifying books in print or periodicals, to identify the pertinent literature relating to a particular topic. Key word or character string search operations may be used to research products or companies in several commercially-available electronic databases. Alternatively, descriptor field searching operations may be performed to search selected data fields only; for example, such operations may be used to locate companies or products by conventional standard industrial codes; to identify publicly-traded companies by stock exchange identifiers; or to identify books by international standard book numbers. Descriptor field searching is usually more efficient, since the full text of the database need not be searched.
The principal difficulty for the operator in performing a plurality of set-creating operations is the coordination and implementation of a search strategy in a user interface that requires frequent user input and manipulation. For example, user interfaces that require the continuous opening and closing of windows or the sorting and storing of data sets introduce significant distraction, which can result in search strategy errors, the loss of data sets, or the performance of incomplete or inconclusive searches. One additional difficulty encountered in set-creating activities is that search strategy decisions are often reevaluated on-the-fly in view of the search results obtained from previous queries. Also, in order to optimize search efficiency and minimize error, it is a common practice to refer to and review previous search queries and/or data sets to verify the accuracy of the query or to perform additional search operations on a previously generated data set. Unfortunately, the current commercially-available user interfaces make it difficult for the operator to quickly and efficiently review the queries and data sets developed in selected levels of a hierarchical search strategy.